Position sensors are among a number of electro-mechanical transducers that may be used to sense a position of an object. For example, position sensors may be configured to sense an actual, or “absolute,” position of an object, as well as a “relative” position, or a displacement, of the object. In some cases, position sensors may be referred to as position “encoders.” A particular position sensor may comprise any of a wide variety of linear and angular, or “rotary,” position sensors. In some examples, position sensors may use contact-based sensing means to sense a position of an object by mechanically coupling the object to the position sensor, e.g., to a movable member or a rotating shaft of the position sensor, which may be mechanically coupled to a sensing element of the position sensor. In other examples, position sensors may employ a wide variety of contactless sensing means, such as optical, magnetic, capacitive, and inductive sensing means, as some examples. Position sensors employing such contactless sensing means may be less susceptible to wear and may provide greater durability compared to contact-based position sensors.
For example, a linear position sensor, or “encoder,” may be configured to sense a position of an object moving along a linear trajectory relative to the linear position sensor. As one example, the linear position sensor may sense a position of an encoder “read-head” that is coupled to the object relative to an encoder track as the encoder read-head and the object move together along the encoder track. The position of the read-head relative to the encoder track may be sensed using mechanical, optical, magnetic, capacitive, or inductive sensing means, as well as other sensing means. As another example, in the case of a linear position sensor employing magnetic sensing means as described above, the linear position sensor may sense a position of a magnetic target that is coupled to the object relative to one or more magnetic field sensors disposed along a base of the linear position sensor. In this example, the magnetic target may be configured to generate a uniform magnetic field that varies relative to the one or more magnetic field sensors based on the position of the magnetic target, and therefore the object, relative to the sensors. Accordingly, the one or more magnetic field sensors may be configured to sense the magnetic field as the magnetic target and the object move together along the base. For example, the one or more magnetic field sensors may include magnetoresistive (MR) sensors, including anisotropic magnetoresistive (AMR) sensors, Hall effect sensors, or other magnetic sensors.